1. Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Ben-Gurion University of the Negev Department of Communication Systems Engineering Supervisors Prof. Michael Segal Mr. Itzik Kitroser Students Dmitry Zelikman Alex Berkman

2. 2Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks 1.Project Goal 2.WiMAX 3.OFDMA 4.Scheduling 5.MMR 6.Screenshots 7.Summary What will we talk about? Roadmap Project Goal OFDMA WiMAX Scheduling MMR Summary

4. 4Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Project Goal Simulate a WiMAX MMR network under the network simulator NS2, and analyze different scheduling and mapping algorithms on this network. 1.Start with WiMAX module created by NIST. 2.Add OFDMA PHY to the module 3.Add Multi-Cell Handovers. 4.Add MMR. 5.Implement and test different algorithms. How ?

6. 6Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks WWAN WMAN WLAN WPAN WiMAX Wireless Networks… IEEE 802.15 Bluetooth IEEE 802.11 Wi-Fi IEEE 802.16 WiMAX Cellular IEEE 802.16 is a standard for high speed, high capacity, long range (metropolitan area) wireless networks.

7. 7Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks WiMAX What can IEEE 802.16 do ? Supports data rates of 1.5Mbps to 70Mbps. Adaptive modulation (QPSK, 16QAM, 64 QAM). Works in LOS and NLOS environment. Works in licensed and license exempt frequencies. Allows mobility and handovers. Supports QoS for different traffic types. Data, audio and video. Has different physical layers SC, SCa, OFDM, OFDMA.

8. 8Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks WiMAX So what is WiMAX ? 1.The market name of IEEE 802.16. 2.Name of the “WiMAX Forum” WiMAX is rapidly developing and has the potential to become the lead standard for 4G networks. Makes sure WiMAX equipments from different manufacturers work together.

10. 10Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks OFDMA Time Orthogonal Frequency Division Multiple Access. Frequency 1011010 OFDMA technology allows using several sub-channels simultaneously with high spectral efficiency, simple hardware, and many other advantages… We know what TDMA and FDMA are. What if we could use both together ?

11. 11Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks OFDMA In order to make it all work, we need scheduling. Time Frequency The BS builds maps that tell every MS when and where it should transmit and receive. We seek an optimal algorithm. Burst 1 Burst 3 Burst 4 Burst 2 Burst 5 Burst 6

13. 13Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks The Scheduling Process A real OFDMA frame… RTG TTG DL Burst 2 DL Burst 3 DL Burst 4 DL Burst 5 DL Burst 6 DL-MAP UL-MAP Preamble FCH A TDD FrameNext Frame DL SubframeUL Subframe Ranging UL Burst 1 UL Burst 2 UL Burst 3 UL Burst 4

14. 14Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MAC Layer The Scheduling Process The scheduling process… Incoming Connection List XYT Bandwidth Requests Z UL Scheduler For the UL Subframe Bandwidth Allocations Ranging UL Burst 1 UL Burst 2 UL Burst 3 UL Burst 4 UL-MAP

15. 15Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MAC Layer DL Subframe The Scheduling Process The scheduling process… Outgoing Connections DL Scheduler For the DL Subframe DL Mapper DL-MAP UL-MAP Burst 2 Burst 3 Burst 4Burst 5 Classifier

17. 17Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MMR – Mobile Multihop Relay In a regular wireless network… Building another base station to keep the customer happy is expensive. If only we had another solution…

18. 18Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MMR – Mobile Multihop Relay In an MMR Network… Relay stations improve the range and capacity of the base station.

19. 19Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MMR – Mobile Multihop Relay All stations connected to the same BS use the same frequency range. How do we avoid collisions and interference ?

20. 20Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MMR – Mobile Multihop Relay The BS takes into account interference between relay stations. RS BS RS The solution is scheduling. This creates the 3D scheduling problem.

21. 21Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks MMR – Mobile Multihop Relay A real MMR frame… RTG TTG DL Burst 2 DL Burst 3 DL Burst 4 DL Burst 5 DL Burst 6 DL-MAP UL-MAP Preamble FCH A FrameNext Frame DL SubframeUL Subframe Access ZoneRelay Zone Access Zone Relay Zone R-MAP FCH R-DL Burst 1 R-DL Burst 2 R-DL Burst 3 R-DL Burst 4 5 R-DL Burst 6 Ranging UL Burst 1 UL Burst 2 UL Burst 3 UL Burst 4 Ranging R-UL Burst 1 R-UL Burst 2 R-UL Burst 3

23. 23Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Screenshots A cellular topology with 9 BS and 50 MS. Base stations are connected by hard links.

24. 24Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Screenshots Single cluster with three base stations. A mobile station is moving from one cell to another.

25. 25Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Screenshots Zoom in on a cell from the previous screenshot.

27. 27Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Summary What did we do ? Implemented OFDMA according to the standard. Mobility and handovers simulation. Basic scheduling and mapping algorithms. Created tools for simulation analysis. Work in progress…  MMR. To be done…  Scheduling algorithm for MMR.

28. 28Analysis of Three Dimensional Scheduling Algorithms in Multi-Hop OFDMA Networks Summary The End